refactor(hooks): rewrite useLocalStorage hook

* return a tuple instead of an object
* add a validator function as parameter (if the stored value
is manually changed, it is not safe to cast its type)
* add tests

1 files changed, 59 insertions, 0 deletions

diff --git a/src/utils/hooks/use-local-storage/use-local-storage.test.ts b/src/utils/hooks/use-local-storage/use-local-storage.test.ts
new file mode 100644
index 0000000..3b63495
--- /dev/null
+++ b/src/utils/hooks/use-local-storage/use-local-storage.test.ts
@@ -0,0 +1,59 @@
+import { describe, expect, it } from '@jest/globals';
+import { act, renderHook } from '@testing-library/react';
+import { LocalStorage } from '../../../services/local-storage';
+import { useLocalStorage } from './use-local-storage';
+
+const validator = (value: unknown): value is string =>
+  typeof value === 'string';
+
+describe('useLocalStorage', () => {
+  const fallback = 'fuga';
+  const key = 'qui';
+
+  it('should return the fallback value when storage is clear', () => {
+    LocalStorage.clear();
+
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+
+    expect(result.current[0]).toBe(fallback);
+  });
+
+  it('should return the stored value when storage is not clear', () => {
+    const storedValue = 'unde';
+
+    LocalStorage.set(key, storedValue);
+
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+
+    expect(result.current[0]).toBe(storedValue);
+  });
+
+  it('should return the fallback value when the stored value is invalid', () => {
+    LocalStorage.clear();
+
+    const storedValue = 42;
+
+    LocalStorage.set(key, storedValue);
+
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+
+    expect(result.current[0]).toBe(fallback);
+  });
+
+  it('can update the stored value', () => {
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+    const newValue = 'eveniet';
+
+    act(() => result.current[1](newValue));
+
+    expect(result.current[0]).toBe(newValue);
+  });
+});